1. Field of the Invention
This invention relates to the field of arc welding. More particularly, the present invention relates to a welding-tool holder that allows an operator to maintain an erect stance while welding decking, floors, and other items that are welded at the level of the operator's feet. Yet more particularly, the present invention relates to a welding-tool holder that can be quickly and conveniently adjusted in length. Finally, the present invention relates to a welding-tool holder that can adapt existing shielded metal arc welding equipment.
2. Description of the Prior Art
Welders who use conventional hand-held arc-welding tools to weld floors, decking, and other work at foot level are forced to maintain a working stance that can result in significant ergonomic, health, and safety problems. These welders must work in uncomfortable, bent-over positions that place strain on their backs and legs. This strain can require frequent work breaks for stretching and relief, and can lead to fatigue, discomfort, pain, and disability. Furthermore, this bent-over working stance places the welder's head near and above the weld site. The welder is thus required to wear a cumbersome conventional welding hood for facial protection from flying sparks, and is nonetheless in a position to inhale the hot and noxious fumes that rise directly up from the welding process. During the welding process, the arc-welding electrode is consumed, and thus continuously shortened. This requires the welder to work ever closer to the weld site as the electrode decreases in length. Welders must compensate for the ever-shortening electrode by bending over farther and bringing their faces ever closer to the sparks and fumes emitted from the weld site.
It is therefore desirable to have a welding-tool holder that will enable a welder to maintain an erect stance while welding at foot level. Kohno et al. (U.S. Pat. No. 4,956,540; Issued 1990) disclose an arc spot-welding apparatus that does permit the welder to weld decking and other items at foot level while standing erect. The Kohno et al. apparatus is a complete self-contained arc spot-welding device composed of an electric power supply, a welding-wire feed system, an extended welding torch, and control and supply cables. The disclosed torch is composed of a welding nozzle assembly, a torch body, and a torch handle. The nozzle assembly contains the wire arc welding electrode, holes for the flow of shielding gas, a shielding nozzle, and an operator-pressure switch to activate the welding system. The torch body consists of cylindrical tubes through which the electrical wires, shielding gas, and wire electrode pass through to the nozzle assembly. The length of the torch body can be varied to accommodate operators of different heights by selecting tubes of the appropriate lengths. The disclosed torch handle protrudes from the torch body at an approximately perpendicular angle and contains a trigger switch used to activate the electric current, wire-electrode feed, and flow of shielding gas to the torch nozzle assembly.
The Kohno et al. apparatus is a complete, self-contained, and elaborate system that is specifically designed for arc spot welding with a wire-feed electrode and, thus, is not applicable to shielded metal arc welding. Even if the Kohno et al. apparatus could be adapted for application to shielded metal arc welding, it suffers from several disadvantages: The length of the torch body of the Kohno et al. apparatus is not adjustable; rather, the welding torch must be disassembled and then reassembled with tubing of a different length to adapt it to the tool-length requirements of an operator of a different height. Furthermore, rather than adapting the existing welding equipment to enable the welder to maintain an upright stance while welding floors or decking at the foot level, the Kohno et al. apparatus is a complete system that would replace or supplement existing equipment, at significant cost.
Gerard (U.S. Pat. No. 4,791,266; Issued 1988) discloses a welding device composed of a system of interconnectible extensions that can encompass a 90.degree. bend at the proximal end of the torch head. This welding device includes a torch head and a composite connecting cable that supplies fluid and electric current to the torch head. It is particularly designed for low-power plasma cutting torches and to permit the convenient insertion of extension cables between the device and its supply sources to allow the operator to weld farther from the sources of electric current and fluid.
While the Gerard apparatus might protect the operator's face and arms by allowing them to be farther from the welding site than is possible with conventional welding tools, it is not designed for simple, conventional, shielded metal arc welding and would require that the user's existing welding equipment be replaced or supplemented. As with the Kohne et al. apparatus, the Gerard apparatus would also require that it be disassembled and reassembled to adapt it to the tool-length requirements of a welder of different height or to compensate the decreasing length of a welding electrode as it is consumed in the welding process.
Glasser (U.S. Pat. No. 3,832,250; issued 1974) discloses a welding hook, i.e., a welding torch with an approximately 180.degree. bend at its distal end designed to permit welding of otherwise inconveniently accessible sites. Though this device increases operator safety by increasing the distance between the operator's hands and face and the welding site, the 180.degree. bend in the Glasser device does not permit direct use of this device to weld decking or other items at the level of the operator's feet.
Several examples of prior art disclose welding torches that have a pistol-grip handle that protrudes approximately perpendicular to the longitudinal axis of the torch. A pistol-grip handle affords the operator a more comfortable operating position in many welding situations. Jenkins (U.S. Pat. No. 4,160,148; issued 1979) discloses a stud welding device featuring such a pistol-grip handle. The Jenkins device is a specialized tool designed for welding studs that fasten insulation to the exterior surfaces of cryogen containers and it cannot be used for conventional shielded metal arc welding.
None of the prior art is directed at shielded metal arc welding in which the shield gas is provided in situ by the coating of the welding electrode. Kohno et al. and Glasser disclose tools designed for arc welding with an external source of shielding gas and a continuously fed wire electrode; Gerard discloses a welding tool especially suitable for use as a plasma cutting torch, and Jenkins a specialized tool for welding studs. Gerard, Glasser, and Jenkins disclose welding devices that would not permit an operator to weld decking or other items at foot level while maintaining an upright stance. All of the prior art discloses tools that would replace or supplement a user's currently existing welding tool. None of the prior art discloses a tool that would adapt a user's currently existing welding tool to permit safer and more convenient shielded metal arc welding at the level of the operator's feet.
Therefore, what is needed is a device for protecting those operators engaged in shielded metal arc welding of floors, decking, and other items at the level of the operator's feet. What is further needed is such a device that makes it possible for the operator to perform such welding while maintaining an upright stance, with arms and face protected from noxious fumes and flying sparks emanating from the welding site. What is yet further needed is such a device that can be quickly and conveniently adjusted in length to accommodate the shortening of the welding electrode as it is consumed by the welding process and to accommodate operators of different heights. Finally, what is needed is such a device that is a simple and inexpensive accessory that can be used with existing shielded metal arc welding equipment.